Subcellular localization of the post-translational events involved in pro-ACTH-endorphin processing (proteolytic cleavages, acetylation, amidation, glycosylation) will be further examined in both intermediate and anterior pituitary. The structure of the NH2-terminal region of mouse and rat pro-ACTH/endorphin (called 16K fragment) will be investigated more completely, in particular to study the oligosaccharide chain(s) and the heterogeneity in 16K fragment. Immunoabsorption methods will be employed to purify the ACTH/endorphin precursor(s) in rat anterior pituitary and hypothalamus, after which comparative peptide analyses using high performance liquid chromatography will be performed. The ACTH/endorphin precursor and its metabolism in lizard pituitary will be further examined.